Ruby on Rails Tutorial
Learn Rails by Example
The Ruby on Rails Tutorial helps you learn Rails by example through the development of a substantial sample application, including a site layout, a user data model, a full registration and authentication system, user-micropost associations, social "following", and a feed of status updates. The Ruby on Rails Tutorial also teaches good software development practices, including version control with Git and GitHub, test-driven development (TDD) with RSpec, and instant deployment with Heroku. Though of necessity the book and screencasts focus on a specific sample application, the emphasis throughout the Rails Tutorial is on general principles, so you will have a solid foundation no matter what kind of web application you want to build.